/*
 * Copyright (c) 2004-2022, University of Oslo
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice, this
 * list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright notice,
 * this list of conditions and the following disclaimer in the documentation
 * and/or other materials provided with the distribution.
 *
 * 3. Neither the name of the copyright holder nor the names of its contributors 
 * may be used to endorse or promote products derived from this software without
 * specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
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 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
package org.hisp.dhis.textpattern;

import java.util.ArrayList;
import java.util.List;
import java.util.Random;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import java.util.stream.Collectors;
import java.util.stream.IntStream;

/**
 * @author Stian Sandvold
 */
public class TextPatternMethodUtils {
  /**
   * Returns a random String based on the format. The format (As specified in TextPatternMethod) can
   * contain '#' digits, 'X' capital letters and 'x' lower case letters.
   *
   * @param random a Random object to generate random numbers
   * @param format the format (as specified in TextPatternMethod)
   * @return the string generated
   */
  public static String generateRandom(Random random, String format) {
    StringBuilder result = new StringBuilder();

    List<Character> uppercase =
        IntStream.range(0, 26).mapToObj((n) -> (char) (n + 'A')).collect(Collectors.toList());
    List<Character> lowercase =
        IntStream.range(0, 26).mapToObj((n) -> (char) (n + 'a')).collect(Collectors.toList());
    List<Character> digits =
        IntStream.range(0, 10).mapToObj((n) -> (char) (n + '0')).collect(Collectors.toList());
    List<Character> all = new ArrayList<>();
    all.addAll(uppercase);
    all.addAll(lowercase);
    all.addAll(digits);

    for (char c : format.toCharArray()) {
      switch (c) {
        case '*':
          result.append(all.get(random.nextInt(all.size())));
          break;
        case '#':
          result.append(digits.get(random.nextInt(digits.size())));
          break;
        case 'X':
          result.append(uppercase.get(random.nextInt(uppercase.size())));
          break;
        case 'x':
          result.append(lowercase.get(random.nextInt(lowercase.size())));
          break;
      }
    }

    return result.toString();
  }

  /**
   * Takes a format (as specified in TextPatternMethod) and attempts to apply it to the text. If
   * there is no match, the method returns null. This can happen if the text don't fit the format:
   * There are more '.' characters than there are characters in the text Both '^' (start) and '$'
   * end characters is present, but there is not an equal amount of '.' as characters in the text
   *
   * @param format the format defined (As specified in TextPatternMethod)
   * @param text the text to perform the format on.
   * @return the formatted text, or null if no match was found.
   */
  public static String formatText(String format, String text) {
    Matcher m = Pattern.compile("(" + format + ")").matcher(text);

    if (m.lookingAt()) {
      return m.group(0);
    }

    return null;
  }
}
